How to use and troubleshoot FireWire target disk mode

Learn how to use and troubleshoot FireWire target disk mode.

This article has been archived and is no longer updated by Apple.

FireWire target disk mode allows a Macintosh computer with a FireWire port (the target computer) to be used as an external hard disk connected to another computer (the host). Once a target computer is started up as a FireWire hard disk and is available to the host computer, you can copy files to or from that volume.

Host computer requirements

Host computers must meet these requirements:

Built-in FireWire port or a FireWire port on a PC card

FireWire 2.3.3 or later

Mac OS 8.6 or later

Target computers

These models can be used as target computers:

iMac (Slot Loading) with Firmware version 2.4 or later

iMac (Summer 2000) and all models introduced after July 2000

eMac (all models)

Mac mini (all models)

Power Mac G4 (AGP Graphics) with ATA drive

Power Mac G4 Cube

Power Mac G4 (Gigabit Ethernet) and all models introduced after July 2000

Note: FireWire Target Disk Mode works on internal PATA or SATA drives only. Target Disk Mode only connects to the master PATA drive on the Ultra ATA bus. It will not connect to Slave ATA, ATAPI, or SCSI drives.

Disconnect all other FireWire devices from both computers before you use FireWire target disk mode. Do not connect any FireWire devices until after you have disconnected the two computers from each other or have stopped using target disk mode.

If "Open Firmware Password" has been enabled the computer will not go into Target Disk mode. More information on Open Firmware Password is available in the "What to do if your Mac doesn't enter FireWire Target Disk Mode" section of this article.

If you will be transferring FileVault-protected home directories (Mac OS X v10.3 or later only), log in as the FileVault-protected user and temporarily turn off FileVault. After transferring home directory contents to the target computer, enable FileVault protection again if you like.

To use FireWire target disk mode

Make sure that the target computer is turned off.

If you are using an Apple portable computer such as a PowerBook or MacBook as the target computer, plug in its AC power adapter.

Use a FireWire cable to connect the target computer to a host computer. The host computer can be powered on.

Start up the target computer and immediately press and hold down the T key until the FireWire icon appears. The hard disk of the target computer should become available to the host computer and will likely appear on desktop. (If the target computer is running Mac OS X v10.4 Tiger, you can also open System Preferences, choose Startup Disk, and click Target Disk Mode. Restart the computer and it will start up in Target Disk Mode.)

When you are finished copying files, locate the target computer's hard disk icon on the desktop of the host computer and drag it to the Trash or choose Eject (or Put Away) from the File menu.